OFF THE POINT: Rookie point guard Iman Shumpert (right) works against the Celtics’ Ray Allen during Sunday’s 106-104 Knicks victory. Shumpert sprained the MCL in his left knee during the game and will miss 2-4 weeks. Photo: N.Y. Post: Charles Wenzelberg

Baron Davis is out at least three more weeks with a sore back. Iman Shumpert is shelved two to four weeks with a sprained left knee. Mike Bibby is not a guarantee for tomorrow’s West Coast-trip opener at Golden State because of back spasms. And Toney Douglas, the Knicks’ de facto starting point guard, is Toney Douglas.

The Knicks’ point-guard position may start jelling in mid-January, but for now it’s enough to give coach Mike D’Antoni nightmares of Nate Robinson.

Weclome to the Knicks’ Christmas hangover.

General manager Glen Grunwald is attempting to sign a point guard for the Knicks’ open roster spot (they have 14 signed players). The club is so desperate D’Antoni was even asked about his former Knicks sparring partner, the 5-foot-7 Robinson, who has been bought out by Oklahoma City.

“We’ll look into it,’’ D’Antoni said, smiling widely.

Don’t start dusting off your old Nate jersey, however. Multiple sources told The Post Robinson is not being considered and the coach was “being nice.” Robinson should have been nicknamed “Fido’’ for all the times he wound up in D’Antoni’s doghouse until he demanded a trade. But it’s a sign of the times Robinson even became an issue for the 1-0 Knicks.

Other free-agent point guards include Marcus Banks, whom D’Antoni coached in Phoenix for two seasons, Earl Boykins or a player from the Development League. D’Antoni talked of signing a point guard as a temporary fill-in, because the Knicks may want that last roster spot eventually open for a forward — possibly Kenyon Martin when he’s available in March.

“You have three point guards, [one] of them is questionable, one is out and one is hurt,” D’Antoni said. “You think maybe we have to do something. We’ll try to rectify the situation.’’

If Bibby has recovered after missing the final preseason game and Sunday’s 106-104 season-opening victory over the Celtics, he will back up Douglas tomorrow. Douglas was his usual up-and-down self in the opener.

“I’ll get in a good practice [today] and get my wind back,’’ said Bibby, who did not practice fully yesterday.

The down note of Sunday’s victory was the Shumpert injury. The first-round pick joined Davis on the shelf after spraining the medial collateral ligament in his left knee on a collision with Boston’s Chris Wilcox. The dynamic rookie had been a frenetic defender, pushed the ball and got off his shot anywhere, anytime.

Carmelo Anthony said Shumpert, who limped onto the practice court yesterday with his left leg covered in wrapping and a bulky brace, could come back better by sitting next to Davis on the bench and learning from him.

Bibby is 33 and D’Antoni has hinted he eventually could supplant Douglas. D’Antoni admitted Douglas isn’t “a classic playmaker.’’

The Knicks fell apart during stretches when Douglas failed to control the flow and shot too much (8 of 19 and 2 of 6 on 3-pointers).

“[Douglas] is going to be who he is; he was OK,’’ D’Antoni said. “He is going to make a big shot. He did — a big 3 at the end of the game. He will get shots, make shots, play hard defensively. He’s not going to be the classic playmaker role, but we have the ball in Melo’s hands a lot.’’

Indeed, the Knicks may rely more on Anthony, who had 37 points Sunday, in his new point-forward role.

“Toney is our point guard,’’ Anthony said. “When that time comes, if I go get the ball, I’ll get the ball. But I’m not trying to take the ball from Toney’s hands.’’

Bibby may be unable to play in any of the three games on the four-day trip. The Knicks visit the Lakers on Thursday and the Kings on Saturday.

The Knicks have also have lost reserve power forward Jared Jeffries for at least a week with a calf strain. Shooting forward Steve Novak is expected to make his debut tomorrow in Jeffries’ stead as the Knicks battle with depth issues.